Sliding door



Sept. l5, 1953 A. T. c. BURRows SLIDING DOOR Filed June 2l, 1950 4 Sheets-Sheet l Sept. 15, 19534 A. T. c. BURRows SLIDING DOOR 4 Sheets-Sheet 2 Filed June 2l, 1950 sept. 15, 1953 Filed June 21, 1950 A. T. c. BURROWS 2,651,816

SLIDING DOOR 4 Sheets-Sheet 3 n//E/vrolC Mtr/nwe Z/ amas Gwmuss @amends Sept 15, 1953 A. T. c. BURROWS SLIDING DOOR 4 Sheets-Sheet 4 Filed June 2l, 1950 Idler/ralf Mur-5 metow CL 'l XW v Patented Sept. 15, 1953 SLIDING DOOR Arthur Thomas Charles Burrows, Hitchin, Engy land, assignor to Geo. W. King Limited, Hitchin, England, aBritish company Application J une 21, 1950, Serial No. 169,459 In Great Britain J une 7, 1949 10 Claims. 1

rlhis invention relates to rsliding doors of the kind which are adapted to be moved back and forth along a horizontal or substantially horizontal path into or away from a closed position.

It is an object 'of Vthe'invention to evolve an arrangement whereby such a door on being moved to a closed position may be caused positively to press or bear against resilient sealing strips or equivalent sealing means disposed around the door opening and thereby to produce an effective seal.

In the specification of my co-pending patent application Serial No. 205,286, led January 10, i951, I have describedv an arrangement for a sliding door of the kind referred to wherein means are associated with the door adapted to impart a vertical movement to the same subsequent to its arrival in the closed position or prior to its movement from such position, such vertical movement being utilised to effect operation of a plurality of latch elements which are located at both the leading and trailing edges of the door and are adapted when the latter is in its closed position to co-operate with fixed brackets or the ,likeV disposed at either side of the door opening in such a manner that, depending upon the direction of vertical movement of said door, the latter will be positively urged towards or away from sealing means disposed around said openings.

in the construction above referred to the arrangement is such that the latch elements will always project outwardly beyond the plane of the door face even when `they are inoperative, i. e. during traverse movement of the door. Due to the presence of such projections at both the leading and trailing edges of the door, there is always the possibility that damage may be caused either to the latch elements themselves or to adjacent fixtures or ttings or even to personnel during traverse movement of the door.

lt is a further object of the invention to avoid the disadvantages inherent in thel prior construction and in accordance therewith the latch elements which are disposed at the leading and trailing edges of the door are so constructed, arranged and adapted to operate as to be retractable behind theplane of the doorvface during traverse movement of the door in either direction therebyallowing the provision of an entirely flush door face without any projections. The arrangement is such that the latch elements will remain retracted during theentire traverse movement of the door and will be operated to engage the fixed brackets or the like and to ef- 2 fect sealing of the door after the latter has completed its traverse motion.

In order that the said invention may be clearly understood and readily carried into effect, the same will be hereinafter more fully described with reference to the accompanying drawings in which:

Figure l is a front elevational view of a sliding door assembly;

Figure 2 is an end view of the assembly shown in Figure i but on a larger scale;

Figure 3 is a front elevational view on an enlarged scale showing a portion of the door assembly and illustrating particularly the mechanism for effecting operation of one set of latch elements;

Figure l is an end View of a portion of the mechanism shown in Figure 3,

Figure 5 is a plan view of a portion of the mechanism shown at the right of Figure 3,

Figures 6 and 7 are a front elevational and end view respectively of an alternative mechanism for effecting operation o1 the latch elements, and

Figure 8 is a part sectional end elevational View of mechanism mounted at the lower part of the door. l l Referring to the drawings it will be seen that the door therein illustrated comprises a rigid panel-like structure designated generally by lil, which is capable of being moved back and forth along a predetermined path from an open to a closed position and vice versa. In the embodiment illustrated the door i@ is suspended by means of a rope or cable ll from two trolleys I2 which are adapted to travel on an overhead track i3, one or both of said trolleys I2 having a drive unit associated therewith in order to provide for traversing movement of the door. Mounted on a third trolley it disposed intermediate the trolleys l2 and also running on the track i3 is a hoist unit designated generally by i5, such unit incorporating an electric driving motor, suitable gearing and a winding drum around which passes a hoist chain or cable Il serving to support a hoist block i8. Freely journalled in the block it is a pulley i8 over which the suspension rope or cable l i is adapted to pass, such rope or cable, as will be apparent from Figure 1, being attached at one end to one of the trolleys i2 and passing thence around freely rotatable sheaves or pulleys it! to the pulley I8 whence it passes around further sheaves or pulleys i9, the other end being attached to the second trolley i2,

The arrangement so far described is such that when, for example, the door ill is to be moved j 'above` described the sealing ofthellatter when in its closed posi 3 from the closed to the open position the motor` of the hoist unit l5 will be operated to effect lifting of said door through a predetermined distance whereafter it will be switched off auto matioally in any convenient manner and the power-operated trolley or trolleys l2' from which said door is suspended will be set in operation to drive the door along the track into its open position. On closing the door a drive is imparted to the power operated trolley or trolleys i2 tov move the door into the door opening. When the door reaches the closed positionthe arrangement is such that the drive to the trolleys l 2 will be automatically discontinued while the motor of the hoist unit will be operated automatically to drive the winding drum in such a"direction as to result in lowering of the hoist block i8 and hence of the door ill. It is only intended(l that the door shall be raised or lowered prior to each l'opening or closing` movement by a comparatively small amount, for example, inthe region of two Vinches or' thereabouts.

The raising or lowering' movementzof the door is `utilised'to eiiectlor control tion as will now be more fully described.

l' Disposed at-each..lateral edge o 'thedoor it, i. e. the leading and trailing edgesyis a series l'of' latch elements .2 Gg'fthe Velements at each edge being spaced iapart=.relatively to each .other and 4*being'interconnected'by means of a connecting simultaneously. The

" 'connecting bar'2i which extends parallel to the edge'- ofthe door Hl is,V pivotally connected to links ment about fixed pivots 1- and trailing edges of the doorare 22 which are in turn capable of angular move- '23 carried by the door.

The respective linkmechanisms on the leading both fitted in the samefplane .and are not offset withrespecvJ -fto 'each-Sother. Thenlarrangement is such that VVVwhen *the I door.' starts its transverse movement 20 -at'the'leading from the: closed position all l oi` theV latch elements 'and trailing edges of said door will beretracted lbehind the plane of .the door face due to an angular movement or the links '`about l their -iixed' pivots. i Again, as the door *reaches 'its'closedrpo'sition and comes to a stand fand'tra'iling edgesv will belowered or project i 'by virtueof a reverse angular movement or ne links 22v until 'each 'one .of'said elements en gages-with a nxedhookunitor bracket 2? disposed 'at lthe appropriate' side of the door opening.

'2 lsuch stop being adapted,

with'lrook units or brackets-24, to cci-'operate with one' of 'thev 'links and vtof-preventfurther down- "ward movement of vthe latch elements, thereby "to ensure an appropriate working clearance.

'Thearrangement is such thatithe projection and retractionofthe latch 'elements Zllrwill take "placeiduring the-initial part ofthe downward "Inovementof theI door and during the iinal part "of 'its upward-movement respectively, the final part of' the'downward movementfand the initial Vpart ofithe'upwardmovement beingutiiised re-x spectively `tofeiectand to' break theseaiing ci `said door.

`Thernovement required tov retract `and project or lower each series of latch ele- "inents 2B' is'deriv'ed` from the relative movement between the door (when. the latter iszV subjected Ato 'the vertical movement' abovedescribed) and a 'dogl or' other attachment25 iixedto the door suspension rope or cable li above referred to.

, part of fthe door and associated' with' the con- .'.lon operation of the lever 25 the "and eiiecting retraction of necting bar 2i, the arrangement being such that master link will thereby lifting the bar 2! the latch elements When the door is be swung upwardly behind the plane of the door.

@flowered to release the pressure of the dog or at- 1 -tachment 25 on the lever 26, the latter is caused to swing inthe reverse direction thereby to efn fect .reverse angular movement of the master 4V'elements 25. Alternatively,

ed to` oooperate with link 3i] and projection or lowering of the latch as shown in Figures 6 and '7, the dog or attachment 2E may be adaptalever orcam 3i, the re- .sultant movement of the latter-beingtransmitted :by means of a shaft'or spindle 32 to :impart an angular rmotionI to themaster link `3Q veither di .rectly' or through the termediate levers; such as are indicated. at 33 'and '34.

medium of a seriesof in- The arrangement isV such that theV dog or `attachment 25' will onlyibe operative. during the highest part of the lifting or lowering motion lofl thev door. lDuringlowering of the door as'soon as the adjustable stop above referred to becomes operative to limit Ithe downward .or projecting Ll l) movement of the latch elements-2Q, the lever 26 or 3l co-operating withtha dog .or 4attachnfient will losecontact with the latter. and further lowering and actual sealing ofthe door will there after take place.

i At' -each lateraredge, il. e. the leading and trailingl edges, the door is provided-at its lower `part with a guideroller 35 .(Fig'ure) adapted during traverseV movement of the door lto run in a guide channel 36 (Figures 2 and 8) in the floor or other surface. As-described in the prior specification above referred to, when the door reaches its closed position and islowered the latch elements 2t and their'connecting bars or rods 2| will, subsequent to projection, have a togglelike action which, owing to the engagement of said latch elements with the xed hook units or brackets 24, will cause the door tobe moved bodily inwardly vwithrespect to ltheplaneof the door opening .to `eiectY sealing of. said door.

' Again, on lifting-of the doorpriorto' thev opening movement thereof, the latch. elementsn zu .will be moved initially and prior tofretractionto force the door outwardly away from the sealing" 1devices.

In orderto allow for thisinward and outward movement of--the door it is necessary that `the guide rollers i35'above referred to. shall also be capable of a retractive andprojective movement in order to be disengaged from and to engage the guide channel 3B on'sealing of the door and onopening of the. latter respectively.v In ythe embodiment illustrated in Figures Zand 8, .each

- guide roller 35 isrotatably mounted on a bar or the like 31 which is supported for free vertical slidingmovementin a slotted tubeor the e likev 38 rigidly lmounted at the edge of thdoor.

Disposed parallel tothe. rstslotted tub'eis a second similartube 39 also mounted at the door edge, in which afs'econdbaror the"lik 40 is adapted to slide, said secondbar having a freely rotatable balljlil fsuitablylm'ounted atthe lower endl thereof. .Both ofthe bars'31..and'.40 are linked together by means of a' slotted link 42 which co-operates respectively with pins 43, 44 carried by said bars vand has an arm or extension 45 disposed at a convenient angle to the slotted portion but lying in the same plane, the outer end of such arm or extension 45 being pivotally connected to the lower part of the connecting bar associated with the latch elements. e

The arrangement described in the rpreceding paragraph is adapted to operate as follows: During the traverse movementl of the door the latch elements 26 are retracted and the guide rollers S5 at each of the leading and trailing edges of the door are in their lowermost positions and in engagement with the guide channel 36. When the door reaches its closed position and is lowered with the resultant projection or lowering of the latch elements 20 into engagement with the iixed hook units 24 the slotted link 42 connecting the two slidable bars 31 and 40 will have an angular motion imparted thereto due to the connection of the arm or extension 45 with the connecting bar 2| associated with said latch elements. The angular movement of the link 42 is adapted to cause the rst bar carrying the guide roller 35 to be lifted vertically to raise said roller clear of the guide channel 36. This action takes place, as will be appreciated'during initial lowering of the door. During further' lowering and sealing of the door the ball 4| associated with the second slidable bar 40 will bear on the floor thereby keepingrconstant the distance between the floor and the point of connection of the arm or extension Vl5 with the connecting bar 2l. As the position of the link 4,2 will be maintained fixed with relation to the connecting bar 2i associated with the latch elements 2U the guide roller 35 will be held in the same height position clear of the floor while the door is finally lowered for sealing and the inward movement thereof takes place. The arrangement is such that when the guide roller 35 is raisedv the link 42 will be in such a position, as shown in chain dotted lines in Figure 8, that the slots therein will be horizontal and will thereby allow the requisite inward movement of the door.

On opening of the door it will be appreciated that during the initial raising movement the latch` elements 20 will be operative to free the door outwardly away from the sealing devices and during that movement the slotted link 42 at each edge of the door will be retained inthe position which it occupied during the final stages of the sealing movement, thereby maintaining the associated guide roller 35 clear of the floor. During the nal stage of the lifting movement of the door with consequent retractive movement of the latch elements 2liv and raising of lthe connecting bar 2i at each edge of said door. the slotted link 42 will be caused to move thereby to project the guide roller 35 downwardly and into engagement with the guide channel 36. With the guide roller 35 in the channel 36 the door may then be driven into the open position on operation of the trolleys associated with the carriage.

Instead of employing a hoistunit for effecting the necessary raising and lowering of the door it may be desirable to provide a lifting unit comprising an electric motor which is coupled, through the medium of a huid' coupling and suitable gearing, to a threaded rod rotatably journalled within the door structure in such a manner that its longitudinal axis is vertical or Substantially so. Mounted on the threaded rod or the like is a correspondinglythreaded memberV4 wardly relatively to the latter. Attached to thethreaded member, which may be constrained to move in suitable wardly due to rotation of the while, when said member is moved downwardly' a corresponding downward movement of the door.1 will result.

In certain cases, as in the case of doors of con-- siderablel weight, it may be desirable to replace: the raising and lowering mechanism hereinbee fore described byra hoist mechanism capable of:` imparting a direct 'lift to the door. For example,v a standard or known type of hoist unit may be,l disposed centrally or substantially centrally with respect to the door such unit being carried by a, suitable carrier having wheels or rollers adapted to engage and to run on the iixed overhead track on which the two trolleys which provide for traverse motion to the door are also adapted to run, the arrangement being such that the carrier will be disposed between said two trolleys. Thehoist unit so provided includes a hoist block'sus` pended therefrom through the medium of a chaire, wire, rope or the like which is associated with a winding drum and passesvaround suitably dis posed sheaves or pulleys, the block being adapted to be raised and lowered in known manner according to the drive imparted tothe winding drum. Freely journalled in the hoist block is al sheave or pulley over which one or more suspension ropes or cables, serving to support the door, is or are adapted to pass. Each suspension rope or cable is conveniently anchored at one end to one of the trolleys running on the fixed overhead track and passes thence around suitably disposed sheaves or pulleys carried by the door and around the hoist block sheave or pulley whence it passes around further sheaves or pulleys carried by the door, the other end be ing anchored to the second trolley on the fixed overhead track. It will be appreciated that suitable means will be provided for controlling the operation of the hoist motor so that raising or lowering of the door will be effected at the appropriate times. As in the embodiment previously described, the abutments for effecting operation of the latch elements on closure of the door will be mounted on or associated with the sus. pension rope or ropes at a convenient point.

I claim:

l. A sliding door assembly comprising a rigid door slidable back and vforth along a predeter-I mined substantially horizontal path into andi out of a position wherein it is adapted to closes a door opening; sealing mechanism for displac-l ing said door transversely of vsaid path into and out of sealing engagement with the door opening and including brackets xedly mounted at either side of the door opening, and latch elements pivotally mounted at the leading and trailing edges of the door and movable between inoperative positions wherein theyv are retracted guides, is a pair of ropes or` cables each of which is adapted to pass from said Y member and around a suitable sheaveor pulley, i its free end being anchored to one of the trolleys 2 on which the door is suspended. The sheaves or pulleys are preferably spaced equidistantly from z the vertical centre line of the door at opposite' sides of the latter, the arrangement being such; that when the threaded member is moved up-I threaded rod in.` the appropriate direction the door will be lifted.

latter on operation of said hoist mechanism, an abutment member associated with said rope 01 cable, a shaft rotatab-ly journalled on said door, an arm xedly mounted on said shaft to cooperate with said abutment member and a linkage mechanism serving to couple said shaft to one of the link elements associated with each of said bars, the arrangement being such that on lifting or lowering of the door the abutment member will be caused to cooperate with the arm thereby t0 cause movement of the bars and retraction or projection of said latch elements from or into operative positions wherein they will engage the brackets to secure the door in its closed position.

7. A sliding door assembly comprising a rigid door suspended from an overhead track so as to -be slidable back and forth along a predetermined substantially horizontal path into and out of a position wherein it is adapted to close a door opening, guide rollers disposed at the lower part of said door for engagement during sliding movement thereof with a fixed track eX- tending along said path below the lower edge of the door, brackets iXedly mounted at either side of the door opening, latch elements pivotally mounted at the leading and trailing edges of the door for movement between retracted inoperative positions wherein they lie behind the plane of the door face and projecting operati e positions wherein they engage the brackets, means movably supporting said guide rollers at the lower edge of Said door for projection and retraction, respectively, into and from operative positions wherein said rollers engage the track below the door, means for lifting and lowering the door through a predetermined vertical distance and means actuated by said lifting and lowering means and operating in response to the vertical movement applied to the door to effect retraction and projection of said latch elements from and into their operative positions and simultaneous projection and retraction of the guide rollers into and from their operative positions.

8. A sliding door assembly comprising a rigid door suspended from an overhead track so as to be slidable back and forth along a. predetermined substantially horizontal path into and out of a position wherein it is adapted to close a door opening, said door having at its lower part guide rollers adapted during sliding movement thereof to engage a xed track extending along said path below the lower edge of the door, brackets xedly mounted at opposite sides of the door opening, a series of link elements pivotally mounted at each of the leading and trailing edges of the door, a bar supported by each series of link elements to lie in a plane parallel to the door edge to which said elements are attached and movable in said plane both vertically and transversely with respect to said path, latch means connected to each of said bars and movable with the latter between inoperative positions retracted behind the plane of the door face and operative positions wherein they project beyond said door face to engage said -brackY ets, stationary vertically extending guide means at the lower part of the door and ya .iacent each of the leading and trailing edges thereof, a member mounted for vertical sliding movement in each of said guide means and carrying one of said guide rollers, a linkage mechanism coupling each of said roller carrying members to the bar at the related edge of the door, means for lifting and lowering the door through a predetermined vertical distance, and means actuated -by said lifting and lowering means and operative in response to the vertical movement applied to the door to impart movement to said bars and thereby to effect retraction and projection of the latch means from and into said operative positions wherein they will engage the brackets thereby to secure the door in its closed position and simultaneous projection and retraction of the guide rollers into and from said operative positions wherein they will engage the track below the lower edge of the door.

9. A sliding door as in claim 8, in which a second member capable of vertical sliding movement is disposed in parallel relationship with respect to each of the iirst mentioned members carrying the guide rollers, link means coupling said rst and second members and having an extension which is in turn pivotally connected to the related bar, and said second member being adapted on projection of the latch means to bear on the iioor or other surface thereby to provide a fulcrum for the link which will allow the latter to eiect raising of said first member.

10. A sliding door as in claim 9, in which said link is coupled to said first and second members by pin and slot connections, the arrangement being such that, on retraction of said first member to bring the guide roller out of engagement with the track, movement of the door laterally with respect to said track will be allowed.

ARTHUR THOMAS CHARLES BURROWS.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 783,093 Belari Feb. 21, 1905 1,077,091 Merritt Oct. 28, 1913 1,709,698 Wiebold Apr. 16, 1929 1,965,223 Eklind July 3, 1934 2,247,885 Lomax July 1, 1941 

